Spectrally sensitized negative emulsion containing silver halide grains of less than 0.18 micron

ABSTRACT

A SILVER HALIDE PHOTOGRAPHIC LIGHT-SENSITIVE EMULSION WHEREIN THE SILVER HALIDE CRYSTALS HAVE A MEAN GRAIN SIZE OF LESS THAN 0.18 MICRON, OR WHEREIN AT LEAST 95% OF THE CRYSTALS HAVE A MEAN GRAIN SIZE OF LESS THAN 0.2 MICRON AND WHEREIN AT LEAST ONE OF THE SENSITIZING DYES REPRESENTED BY THE FOLLOWING FORMULAE ARE INCORPORATED IN SUCH AN EMULSION IN AN AMOUNT OF FROM 1 TO 150 MG. PER 1 KG. OF THE EMULSION:   (-N(+)(-R)-(V,V1-1,2-PHENYLENE)-Z-)&gt;C-L1=L2-L3=C&lt;(-Z&#39;&#39;-   (W,W1-1,2-PHENYLENE)-N(-R1)-) (X(-))N (I)   (=N(+)(-R7)-(V2,V3-1,2-PHENYLENE)-Z-)&gt;C-L=(L-L)M=C&lt;   (-Z&#39;&#39;-(W2,W3-1,2-PHENYLENE)-N(-R8)-) (X(-))N (II)   1-R14,2-((-Z2-(W4,W5-1,2-PHENYENE)-N(-R15)-)&gt;C=L-),V4-   QUINOLINIUM (X(-))N (III)   (-N(-R17)-Z3-)&gt;C=(L-L)M=C&lt;(-Q-CO-) (IV)   (-(CH=CH)M2-N(-R19)-Z4-)&gt;C=L5-L6=C&lt;(-Q1-C(=L7-C&lt;(-Z5-N(+)   (-R21)=(CH-CH)M2=))-N(-R20)-CO-) (X(-))N (V)

United States Patent O1 iice 3,706,570 Patented Dec. 19, 1972 3,706,570 SPECTRALLY SENSITIZED NEGATIVE EMULSION CONTAINING SILVER HALIDE GRAINS OF LESS THAN 0.18 MICRON Yoshiyuki Nakazawa, Tohru Sueyoshi, Akira Sato, and Yashiharn Nakarnura, Kanagawa, Japan, assignors to Fuji Photo Film Co., Ltd., Kanagawa, Japan No Drawing. Filed May 18, 1970, Ser. No. 38,485 Claims priority, application Japan, May 17, 1969, Ml/38,248 Int. Cl. GllSc 1/18 US. Cl. 96137 Claims ABSTRACT OF THE DISCLOSURE X- N W1 Formula (11) Formula (IV) Formula (V) ,'Q.1-

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a silver halide spectrally sensitized photographic emulsion, and in particular to a fine-grain silver halide photographic emulsion of a type whose light sensitivity in the specific absorption wave length region of the silver halide is remarkably increased when the silver halide emulsion is subjected to a spectral sensitization by using a specific sensitizing dye.

Description of the prior art It is well known among the techniques of producing silver halide photographic emulsions to enlarge the light sensitive wave length region of a silver halide emulsion by adding some kind of sensitizing dye to the emulsion; but when a silver halide emulsion containing silver halide crystals of ordinary grain size is subjected to the spectral sensitization, the light sensitivity in the specific absorption region of the silver halide is generally decreased.

This phenomenon is generally termed desensitization by a sensitizing dye. Therefore, the selection of sensitizing dyes showing less of such a desensitizing action is desired for producing silver halide photographic light sensitive materials.

On the other hand, in order to improve the quality of images of silver halide photographic light-sensitive materials, it is preferable that the grain size of the silver halide crystals in the silver halide emulsion be as small as possible, which results in, however, a decrease in the sensitivity thereof.

Accordingly, it is difficult to produce a silver halide emulsion containing silver crystals having a grain size as small as possible and yet having a sufiiciently high sensitivity by applying to the silver halide emulsion, a chemical sensitization such as a sulfur sensitization or a reduction sensitization.

The present inventors have discovered that when a silver halide emulsion containing silver halide crystals having a mean grain size of smaller than 0.18 micron, or at least of which are smaller than 0.2 micron, is subjected to a spectral sensitization using a specific sensitizing dye by a conventional method, the photosensitivity in the specific absorption wave length region of the silver halide is remarkably increased and, in addition, the light sensitive Wave length region is enlarged.

A Capri Blue effect, another well-known phenomenon is an increase in light sensitivity in the spectral absorption wave length region of a silver halide caused by a sensitizing dye. This efiect is due to an intense exposure over a short period of time of a silver halide emulsion when a desensitizing dye or a sensitizing dye is incorporated into the emulsion which has not been subjected to a sulfur sensitization or a reduction sensitization.

The elfect discovered by the inventors of the present invention is extremely difierent from the Capri Blue eflFect in that even if the silver halide emulsion containing silver halide crystals having the above-mentioned grain size has been subjected to a sulfur sensitization, a reduction sensitization, or a gold sensitization, the light sensitivity in the specific absorption wave length region of the silver halide is further greatly increased when the silver halide emulsion is spectrally sensitized by a specific sensitizing dye.

Thus, an object of the present invention is to provide a silver halide photographic emulsion having an enlarged spectral absorption wave length region and an increased light sensitivity in the specific absorption wave length region of silver halide by applying to the fine grain silver halide emulsion a spectral sensitization.

SUMMARY OF THE INVENTION The present invention provides a silver halide photographic light-sensitive emulsion wherein the silver halide crystals have a mean grain size of less than 0.18 micron, or wherein at least 95% of the crystals have a mean grain size of less than 0.2 micron, and wherein at least one of the sensitizing dyes represented by the following formulae are incorporated in such an emulsion in an amount of from 1 to mg. per 1 kg. of the emulsion.

Formula (I) The various substituents of the above-formulae are described below in detail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The above object of the present invention can be achieved by incorporating at least one of the sensitizing dyes represented by the following general Formulae I, II, III, IV, and V in a silver halide emulsion containing silver halide crystals having a mean grain size of smaller than 0.18 micron, or at least 95% of which are smaller than 0.2 micron in diameter.

Formula (I) wherein Z and Z each represents an oxygen atom, a sulfur atom, a selenium atom, NR N--R CH=CH, or R and R each represents an alkyl group having 1-4 carbon atoms (such as a methyl group, an ethyl group, etc.), a substituted lower alkyl group (such as a fl-hydroxyethyl group, a fl-methoxyethyl group, a 'y-acetoxypropyl group, a fl-carboxyethyl group, a 'y-sulfopropyl group, etc.), an aryl group (such as a phenyl group), or an allyl group; R and R which may be mutually bonded through a polymethylene chain to form a ring, each represents an alkyl group having 14 carbon atoms, a substituted lower alkyl group (such as ,B-phenylethyl group, etc.), an aryl group (such as a phenyl group), or an allyl group.

When Z and Z' are each an oxygen atom, each of V, V W and W is a hydrogen atom or at least one of them is a phenyl group or a carboxyl group.

When Z and Z' are N-R or NR each of V, V W and W is a hydrogen atom or at least one of them is a halogen atom, an alkyl group having 1-4 carbon atoms,

an alkoxyl group, a hydroxyl group, an acetyl group, a benzoyl group, a carboxyl group, an alkoxycarbonyl group, a nitrile group, a carbamoyl group, an a1kylcar bamoyl group, a sulfamoyl group, an alkylsulfamoyl group, an acetylamino group, an alkylamino group, a trifiuoromethyl group, a trifluorornethylsulfonyl group, or an alkylsulfonyl group.

When Z and Z are a sulfur atom or a selenium atom, at least one of V, V W and W is an alkoxyl group, a phenyl group a hydroxyl group, or a halogen atom.

When Z and Z are CH=CH, each of V, V W and W is a hyrogen atom or at least one ofthem is an alkyl group having 1-4 carbon atoms, an alkoxyl group, a hydroxyl group, a dimethylamino group, or a halogen atom.

When Z and Z are each of V, V W and W is a hydrogen atom or at least one of them is a halogen atom, an alkyl group havirig 1-4 carbon atoms, an alkoxyl group, a hydroxyl group, a phenyl group, or a dimethylamino group.

R and R of Formula I each represents an alkyl group having l-4 carbon atoms, a substituted lower alkyl group (such as a li-hydroxyethyl group, a fi-carboxypropyl group of a -sulfopropyl group), or an allyl group.

L L and L each represents CH or CR m, wherein R represents a hydrogen atom, an alkyl group having 1-4 carbon atoms, an aryl group (such as a phenyl group), or a substituted aryl group (such as an o-carboxyphenyl group, a p-hydroxyphenyl group, etc.); and wherein L or L may be bonded to R or R respectively, through a polymethylene chain; and wherein L and L or L and L may be bonded together through a polymethylene chain; and wherein V and V or W and W may form a benzene ring.

X represents an anion (such as the ions: halogen, perchlorate, thiocyanate, p-toluene sulfate, benzenesulfate, ethylsulfate, methylsulfate, etc.); and n is 0 or 1 (when n is 0, the formula forms an intermolecular salt).

Formula (11) R1 Ra atom,

or CH=CH; wherein R and R each represents an alkyl group having l-4 carbon atoms, or a substituted lower alkyl group (such as a fi-hydroxy ethyl group, a B-methoxy ethyl group, a 'y-acetoxypropyl group, a fl-carboxyethyl group, a 'y-sulfopro-pyl group, etc.); R and R which may be bonded to each other through a polymethylene chain, each represents an alkyl group having 14 carbon atoms, a substituted lower alkyl group (such as a fi-phenylethyl group, etc.), an aryl group (such as a phenyl group) or an allyl group; all of the substituents V V W and W are a hydrogen atom or at least one of them is an alkyl group having 1-4 carbon atoms, an alkoxyl group, a hydroxyl group, a phenyl group, or a halogen atom; wherein V and V or W and W may form a benzene ring; R, and R each represents an alkyl group having 1-4 carbon atoms, or a substituted lower alkyl group (such as a ,B-hydroxyalkyl group, a B-carboxyethyl group, a -sulfopropyl group, etc.); L represents CH, CH or CR wherein R is a lower alkyl group, an alkoxyl 5 group, a hydroxyl group, a halogen atom; wherein two L substituents may be bonded to each other by a polymethylene chain or an alkyl-, alkoxy-, arylor hydroxysubstituted polymethylene chain; R and R each may be bonded to L at the a-position through a polymethylene chain to thereby form a ring; X represents an anion (such as the ions: halogen, perchlorate, thiocyanate, p-toluene sulfonate, benzene sulfate, ethylsulfate, methyl sulfate, etc.), m is 2 or 3; and n is or 1 (when n is 0, the formula forms an intramolecular salt).

Formula (III) wherein Z represents an oxygen atom, a sulfur atom, a selenium atom, N--R or CH=CH; at least one of V W and W being a hydroxyl group or a dialkylamino group; W and W may form a benzene ring; R and R each represents an alkyl group having 1-4 carbon atoms, a substituted lower alkyl group (such as fi-hydroxyethyl group, a fi-methoxycarbonylethyl group, a 'y-sulfopropyl group, a B-carboxyalkyl group, etc.), or an allyl group; L represents --CH=; R represents a lower alkyl group (such as a methyl group, an ethyl group, etc.) or a substituted lower alkyl group (such as a fl-hydroxyethyl group, etc.); R may be bonded to L through a polymethylene chain; X represents an anion (such as the ions: halogen, perchlorate, thiocyanate, p-toluene sulfonate, benzene-sulfonate, methylsulfate, ethylsulfate, etc.); and n is 0 or 1 (when n is 0, the formula forms an intramolecular salt).

Formula (IV) Wherein Z represents an atomic group necessary to complete a S-membered or 6-membered heterocyclic ring such as a nucleus of the benzoxazole series (e.g., benzoxazole, S-chlorobenzoxazole, S-bromobenzoxazole, S-methylbenzoxazole, S-ethylbenzoxazole, S-methoxybenzoxazole, S-ethoxybenzoxazole, S-acetaminobenzoxazole, S-phenylbenzoxazole, 6-chlor0benz0xazole, 7-chlorobenzoxazole, etc.), a nucleus of the benzothiazole series (e.g., benzothiazole, 4-chlorobenzothiazole, 7-chlorobenzothiazole, S-chlorobenzothiazole, 4-phenylbenzothiazole, 4-methoxybenzothiazole, 4-methylbenzothiazole, S-bromobenzothiazole, 5- acetaminobenzothiazole, S-iodobenzothiazole, S-dimethylaminobenzothiazole, 5 methylbenzothiazole, 5,6 dimethylbenzothiazole, S-methoxybenzothiazole, S-ethoxybenzothiazole, S-phenylbenzothiazole, G-methylbenzothiazole, 5,fi-diphenylbenzothiazole, 6-chlorobenzothiazole, 6-methoxybenzothiazole, 6-ethoxybenzothiazole, etc.), a nucleus of the benzoselenazole series (e.g., benzoselenazole, 5-chlorobenzoselenazole, etc.), a nucleus of the a-naphthothiazole series, a nucleus of the B-naphthothiazole series, a nucleus of the a-naphthoxazole series, a nucleus of the p-naphthoxazole series, a nucleus of the a-naphthoselenazole series, a nucleus of the fi-naphthoselenazole series, a nucleus of the thiazoline series, a nucleus of the thiazolidine series, a nucleus of the simple thiazole series (e.g., 4-methylthiazole, 4-phenylthiazole, 4- (2-thienyl)thiazole, etc.), a nucleus of the simple selenazole series (e.g., 4-methylselenazole, 4-phenylselenazole, etc.), a nucleus of the oxazolidine series, a nucleus of the simple oxazole series (e.g., 4-methy1oxazole, 4-phenyloxazole, etc.), a nucleus of the quinoline series (e.g., quinoline, 6-methylquinoline, 6-methoxyquinoline, etc.), a nucleus of the tetrazole series, a nucleus of the pyridine series, a nucleus of the tetrahydro pyrrole series, a nucleus of the 2,3,3-substituted-3H-benz[g]-indole series, a nucleus of the 3,3-dialkyl indolenine series (e.g., 3,3-dimethylindolenine, etc.), etc.; wherein Q represents an atomic group necessary to complete a ketomethylene heterocyclic ring, such as a rhodanine nuclei (e.g. unsubstituted rhodanine, 3-ethylrhodanine, 3-fi-hydroxyethyl rhodanine, 3-carboxymethyl rhodanine, 3-,8-sulfoethyl rhodanine, 3- (1,3-dicarboXy-n-propyl) rhodanine, 3 a carboxyethyl rhodanine, 3-p-carboxyphenyl rhodanine, 3-(3-carboxy-4- hydroxyphenyl)rhodanine, 3-p-sulfophenyl rhodanine, 3- (2,5-disulfophenyl)rhodanine, 3-phenyl rhodanine, 3-pdimethylaminophenyl rhodanine, etc.), a 2-thio-2,4(3,5)- oxazoledione nuclei (e.g., 3-ethyl-2-thio-2,4(3,'5)-oxazoledione, 3-p-sulfophenyl 2 thio-2,4( 3,5 )-oxazoledione, 3- carboxymethyl-2-thio-2,4(3,5)-oxazoledione, 3 carboxymethyl-Z-thio 2,4(3,5) oxazoledione, 3-sulfomethyl-2- thio-2,4(3,5)-oxazoledione, etc.), a Z-thiohydantoin nuclei (e.g., unsubstituted-Z-thiohydantoin, 1,3-diphenyl-2-thiohydantoin, 3-ethyl-1-phenyl-2-thiohydantoin, l-methyl-Z- thiohydantoin, 1-carboxymethyl-3-phenyl-2-thiohydantoin, etc.), a S-pyrazolone nuclei (e.g. l-phenyl-3-methyl-5- pyrazolone; 3 methyl-l-(Z-benzothiazolyl)-5-pyrazolone; 3-methyl-1-(2-benzothiazolyl) 5 pyrazolone; 3-carboxymethyl-l-phenyl 5 pyrazolone; l-carboxyphenyl-S- methyl-S-pyrazolone; 3-methyl-1-p-sulfophenyl 5 pyrazolone; 1-(4-sulfo 1 naphthyl)-3methyl-5-pyrazolone; 1-(4-sulfo-l-naphthyl)-3-methyl-5-pyrazolone; etc.); a 4- thiazolidone nuclei; a 2-arnino-4(5)-thiazole nuclei (e.g. 2-diphenylamino-4(5 thiazolone; 2-diethylamin0-4 (5 thiazolone; etc.); a 2-alkylmercapto-4(5)thiazolone nuclei (e.g. 2-methyl mercapto-4(5)-thiazolone; Z-ethylmercapto-4(5)thiazole, etc.); a barbituric acid nuclei (e.g. unsubstituted barbituric acid; 2-thiobarbituric acid, etc.) and the like; wherein R represents an alkyl group having 1-4 carbon atoms, a substituted lower alkyl group (such as a ,B-hydroxyethyl group, a 'y-sulfopropyl group, a 3- carboxyethyl group, etc.) or an allyl group; L represents CH, CH or CR wherein R represents a substituted lower alkyl group (such as a fi-carboxyethyl group, a 'yhydroxypropyl group, etc.), or a substituted aryl group (such as an o-carboxyphenyl group, a p-hydroxyphenyl group, etc.); R and L may be bonded to each other through a polymethylene chain, wherein L represents the L nearest to the heterocyclic ring containing Z and m is 1 or 2.

Formula (V) wherein Q represents an oxygen atom, a sulfur atom, or NR Z and Z each represents an atomic group necessary to complete a S-membered or 6-membered heterocyclic ring; R R and R each represents a lower alkyl group, or a substituted lower alkyl group (such as a B-hydroxyethyi group, a fi-ca-rboxyethyl group, a y-sulfopropyl group, etc.); L L and L each represents CH or CR R represents a lower alkyl group, an alkoxyl group (such as a methoxy group, etc.), an aryl group (such as a phenyl group), or a substituted aryl group (such as a o-carboxyphenyl group, a p-hydroxyphenyl group, etc.); R represents a lower alkyl group, a substituted lower alkyl group (such as a B-hydroxyethyl group, etc.), an aryl group (such as a phenyl group, etc.), or an allyl group; m is 0 or 1; X represents an anion (such as the ions: halogen, perchlorate, thiocyanate,

11 TABLE 4 TABLE 5Continued Dye Dye 59 H coon 6 s on-i- S CHCH=C-S s 8 CH3 N :L J: N o A 0 N OH I 21 15 N aH1 N 47211] 2H5 A:

10 I 2B5 60 s C|H|OH OBI-OH s f; o N/ N S\ I (3,11, 0 CH-CH J; N/ 61 o 2H5 S I- $2118 CHI-CH 1 69.... CH; CH: \N

O t'snsnooon CH-GH s S Q 62 .3

\N ol J=CH N COOH (12m l 8 I 2H3 LIZJKCH 1 s 70.- NNCH:

Ii 011-011 S S $211. 0 L011 63 s N an s e z:

H s I 2 I N 0 71.--. s s I N CH-CH HI (,7 40 CH] 2H 0 o j\+ 64 0:; I l N C 4 N H1 hH OOH N S C zHg 1- CH 8 72 S o CHCH OH; N o f O 0 him i i 3/ HPCH=CH2 IJaH7 ('h TABLE 5 Dye 2H I- GIL-CH1 1 CH 8 N 0 CH: 5 S (ljgm N fi =cH-c- 6 (5211 021150 N O OH a 65..-. 0 0211 If If I O 0 02H; CzHs 011-011 I HaC 0H N 01 CH; I l fi N I? 5 02H When the sensmzing dyes described above are used I together with the silver halide photographic emulsions 66.-.. N--N-CH; containing silver halide crystals having a mean grain size of smaller than 0.18 micron or at least of which have a grain size of smaller than 0.2 micron according to the present invention, not only is the light sensitive wave length region of the silver halide photographic emulsion enlarged by the essential action of the sensitizing dyes, but also the light sensitivity in the specific absorption wave length region of the silver halide can be increased.

The aforesaid effect is particularly remarkable with respect to gelatino silver halide photographic emulsions, but is also effective on other silver halide photographic emulsions employing other hydrophilic colloids than, gelatin, such as agar agar, collodion, water-soluble cellulose derivatives, polyvinyl alcohol, or other synthetic or natural hydrophilic resins.

The silver halide used in the silver halide photographic emulsion of this invention may be silver chloride, silver chlorobromide or silver iodobromide, but the use of silver chlorobromide or silver iodobromide is most preferable.

The sensitizing effect on the specific absorption wave length region of silver halide in the present invention largely depends on the grain size of the silver halide crystals. That is, in silver halide photographic emulsions having the same silver halide composition, the effect of the sensitizing dye on such silver halide emulsions is varied according to the grain size of the silver halide crystals incorporated in the emulsion, and if a photographic emulsion containing silver halide crystals having a mean grain size of larger than 0.18 micron in diameter is employed, the sensitizing dyes mentioned above show no sensitizing effect in the specific absorption wave length region of the silver halide.

This is shown by the following:

The sensitizing ratio shown in the above table is a ratio of the sensitivity of a silver halide photographic emulsion, containing the sensitizing dye of the present invention, to the sensitivity, which is assumed to be 1, of a silver halide photographic emulsion containing no sensitizing dye.

From Table 6, it will be understood that the influence of the grain size of the silver halide crystals on the sensitizing efiect is very large.

For preparing the silver halide spectrally sensitized photographic emulsion according to the present invention, at least one of the above-mentioned sensitizing dyes may be incorporated by a conventional method in a silver halide photographic emulsion chemically sensitized by an unstable sulfur compound and a gold complex salt.

In practice, the sensitizing dye is usually added to the silver halide emulsion as a solution thereof in a proper solvent such as methanol or ethanol. The proportion of the sensitizing dye to be incorporated in the silver halide emulsion may be varied over the wide range of 1-150 mg. per one kg. of the emulsion according to the desired sensitizing effect.

Furthermore, the silver halide photographic emulsion of the present invention may be further subjected to a super-sensitization and a hyper-sensitization.

Into the silver halide photographic emulsion of the present invention may further be incorporated ordinary additives such as other chemical sensitizing dyes, a stabilizer, an anti-foggant, a color toning agent, a hardening agent, a surface active agent, a plasticizer, a developing accelerator, a color coupler and a fluorescent brightening agent, by conventional means.

The invention will be explained further by reference to the following non-limiting example.

EXAMPLE Silver halide photographic emulsions were prepared by incorporating the sensitizing dyes shown in Table 8 below in a silver iodobromide emulsion (AgI:AgBr=1 99-mole ratio) The photographic emulsion was applied to a cellulose triacetate film and dried to provide a photographic lightsensitive film. The light-sensitive film was exposed to a 14 lamp of 8,000 luxes (2854 K) through an interference filter ()t ==397.5 millimicrons and A1 /2=16 millimicrons) and then developed in a developer having the following composition.

TABLE 7 Metol 2 Hydroquinone 8 Anhydrous sodium sulfite Anhydrous sodium carbonate 45 Potassium bromide 5 Water to make 1 liter.

In Table 8 is shown the sensitizing ratio in the specific absorption wave length region of the silver halide when the sensitizing dye shown in the table was incorporated in the silver halide emulson containing silver halide crystals having a mean grain size of 0.07 micron. Also, in Table 9 are shown the sensitizing ratios when the sensitizing dyes 3, 11 and 22 were added to silver halide emulsions containing silver halide crystals having different mean grain sizes, respectively.

Furthermore, in Table 10 are shown, by way of comparison, the sensitizing ratios in the specific absorption wave length region of silver halide obtained by incorporating the typical sensitizing dyes of this invention selected from Table 8 and the sensitizing ratios obtained by incorporating control sensitizing dyes therein.

The sensitizing ratios employed in the following tables have the same meaning as those in Table 6.

TABLE 8 Amount Amount (mg. Sensi- (mg. Sensimole/kg. Emultizing mole/kg. Emultizing Dye emulsion) sion ratio Dye emulsion) sion ratio 0.1 AgBrI 4. 5 0. 1 .AgBrI 6 0. 1 AgBrI 0.1 AgBrI 6 0. 1 AgBrI 0. 1 AgBrI 5 0. 1 AgBrI 3. 5 0. 1 .AgBrI 4 0. 1 AgBrI 10 0. 1 AgBrI 4 0.1 AgBrI 7 0. 1 AgBrI 5 0. 1 AgBrI 11 0. 1 AgBrI 4 0. 1 AgBrI 9 0. 1 AgBrI 10 0. 1 AgBrI 6 0. 1 AgBrI 25 O. 1 AgBrI l2 0. 1 AgBrI 4 0. 1 AgBrI l0 0. l AgBrI 5 0.1 AgBrI 6 0. 1 AgBrI 8 0.1 AgBrI 10 0.1 AgBrI 5 0. 1 AgBrI 9 0. 1 AgBrI 4 0. 1 AgBrI 5 0. 1 AgBrI 7 0. 1 AgBrI 5 0.1 AgBrI 5 0. 1 AgBrI 10 0. 1 AgBrI 9 0. 1 AgBrI 5 0. 1 .AgBrI 10 0.1 AgBrI 5 0. 1 AgBrI 0 0. 1 AgBrI 10 0. 1 AgBrI 6 0.1 AgBrI 7 0. 1 AgBrI 10 0. 1 AgBrI l0 0. 1 AgBrI 6 0. 1 AgBrI 5 0. 1 AgBrI 5 0. 1 AgBrI 10 0. 1 AgBrI 5 0. l AgBrI 6. 5 0. 1 AgBrI 5 0.1 AgBrI 4 0. 1 AgBrI 5 0. l AgBrI 4 0. 1 AgBrI 4, 5 0. 1 AgBrI 4 0. 1 AgBrI 6 0. 1 AgBrI 10 O. 1 AgBrI 11 0.1 AgBrI 5 0. 1 .AgBrI 10 0. 1 AgBrI 20 0.1 AgBrI 6 0. 1 AgBrI 5 0. 1 AgBrI 7 0. 1 AgBrI 5. 5 0. 1 AgBrI 4 0. 1 AgBrI 5 0. 1 AgBrI 7 0. 1 AgBrI 6 0. 1 AgBrI 7 0.1 AgBrI l2 0. 1 AgBrI 7 0. 1 AgBrI 12 0. 1 AgBrI 9 TABLE 9 Mean grain size diameter, micron sensitizing dye O. 07 0. l0 0. 15 0. 20

The chemical structures of the control sensitizing dyes used in the above table are as follows:

(OHzhSOr laHu aHN 2115):

/Se S @910 What is claimed is:

1. A negative silver halide photographic emulsion comprising a silver halide light-sensitive emulsion containing silver halide crystals having a mean grain size of smaller than 0.18 micron or at least 95% of which have grain sizes of smaller than 0.2 micron in diameter and having incorporated therein from 1 to mg. per kg. of emulsion, at least one of the sensitizing dyes represented by the following Formulae I, II, III, IV and V:

Vi T 1 R R1 wherein Z and Z each represents an oxygen atom, a sulfur atom, a selenium atom, CH=CH, NR N-R wherein R and R each represents an alkyl group having from 1 to 4 carbon atoms, a substituted lower alkyl group, an aryl group, or an allyl group and R and R each represents an alkyl group having from 1 to 4 carbon atoms, a substituted lower alkyl group, an aryl group, or an allyl group, or wherein R and R as defined are bound to each other through a polymethylene chain; wherein R and R each represents a lower alkyl group, a substituted lower alkyl group or an allyl group; wherein L L and L each represents CH or CR wherein R represents a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, an aryl group, or a substituted lower aryl group wherein said L or said L may be bonded to said R or said R respectively, through a polymethylene chain; wherein said L and L or said L and L may be bonded together through a. polymethylene chain; and wherein said V and V or said W and W may form a benzene ring; with the proviso that when Z and Z' are each an oxygen atom, all of V, V W and W are a hydrogen atom or at least one of them is a phenyl group or a carboxyl group; with the further proviso that when Z and Z are N-R or NR all of V, V W, and W are a hydrogen atom or at least one of them is a halogen atom, and alkyl group having from 1 to 4 carbon atoms, a carboxyl group, an alkoxy group, a hydroxyl group, an acetyl group, a benzoyl group, an alkoxycarbonyl group, a nitrile group, a carbamyol group, a sulfamoyl group, an alkylsulfamoyl group, an acetylamino group, an alkylamino group, a trifluoromethyl group, a trifluoromethylsulfonyl group, or an alkylsulfonyl group; with the further proviso that when Z and Z are a sulfur atom or a selenium atom, at least one of V, V W, and W is an alkoxyl group, a phenyl group, a hydroxyl group, or a halogen atom; with the further proviso that when Z and Z are each CH=CH, all of V, V W, and W are a hydrogen atom or at least one of them is an alkyl group having from 1 to 4 carbon atoms, an alkoxyl group, a hydroxyl group, a dimethylamino group or a halogen atom; with the further proviso that when Z and Z are each wherein Z and Z each represents an oxygen atom, NR NR a sufur atom, a selenium atom,

or CH=CH; wherein R and R each represents an alkyl group having from 1 to 4 carbon atoms or a substituted lower alkyl group and R and R which may be bonded to each other through a polymethylene chain, each represents an alkyl group having from 1 to 4 carbon atoms, an aryl group or an allyl group; all of V V W and W are a hydrogen atom or at least one of them is an alkyl group having from 1 to 4 carbon atoms, an alkoxyl group, a hydroxyl group, a phenyl group, or a halogen atom; wherein V and V or W and W may form a benzene ring; wherein R and R each represents an alkyl group having from 1 to 4 carbon atoms or a substituted lower alkyl group; wherein L represents CH, CH or CR11, wherein R represents a lower alkyl group, an alkoxyl group, a hydroxyl group, or a halogen atom; wherein two of said L substituents may be bonded to each other through a polymethylene chain or an alkyl-, alkoxy-, arylor hydroxy-substituted polymethylene chain; wherein R and R may be bonded to said L at the u-position thereof through a polymethylene chain; wherein X represents an anion; m is 2 or 3; and n is 0 or 1; said formula forming an intramolecular salt when n is 0;

(III) 18 methylene chain; X represents an anion; and n is 0 or 1; said formula forming an intramolecular salt when n is 0;

r r Z3 N L-L m,=

R17 (IV) wherein 2;; represents an atomic group necessary to complete a S-membered or 6-membered heterocyclic ring; Q represents an atomic group necessary to complete a ketomethylene heterocyclic ring; R represents an alkyl group having from 1 to 4 carbon atoms, a substituted lower alkyl group, or an allyl group; L represents CH or C-R wherein R represents a substituted lower alkyl group or a substituted aryl group; wherein said R may be bonded to L through a polymethylene chain, wherein L represents the L nearest to the heteroyclic ring containing Z and m; is 1 or 2;

wherein Q represents an oxygen atom, sulfur atom, or N-R Z and Z each represents an atomic group necessary to complete a S-membered or 6-membered heterocyclic ring; R R and R each represents a lower alkyl group or a substituted lower alkyl group; L L and L each represents CH or C-R22, wherein R represents a lower alkyl group, an alkoxyl group, an aryl group or a substituted aryl group; R represents an alkyl group having from 1 to 4 carbon atoms, a substituted lower alkyl group, an aryl group, or an allyl group; m is 0 or 1; X represents an anion; and wherein said R and L or said R and R may be bonded to each other through a polymethylene chain.

2. The negative silver halide photographic emulsion of claim 1, wherein said substituted lower alkyl group R, 1 3, 4 7 a 9, 10 14, 15, 1? 18 19 20 or R is B-hydroxyethyl, -hydroxypropyl, fi-methoxyethyl, 'y-acetoxypropyl, carboxymethyl, B-carboxyethyl, fi-carboxpropyl, y-carboxypropyl, 'y-sulfopropyl, vS-sulfobutyl, or sulfoamyl.

3. The negative silver halide photographic emulsion of claim 1, wherein said substituted lower alkyl group R or R is a B-phenylethyl group.

4. The negative silver halide photographic emulsion of claim 1, wherein said substituted aryl group R or R is o-carboxyphenyl or p-hydroxyphenyl.

5. The negative silver halide photographic emulsion of claim 1, wherein said substituted lower alkyl group R or R is )S-phenylethyl.

6. The negative silver halide photographic emulsion of claim 1, wherein said substituted lower alkyl group R or R is p-hydroxyethyl.

7. The negative silver halide photographic emulsion of claim 1, wherein said heterocyclic ring completed by Z is a nucleus of the benzoxazole series, a nucleus of the benzothiazole series, a nucleus of the benzoselenazole series, a nucleus of the ot-naphthothiazole series, a nucleus I of the B-naphthothiazole series, a nucleons of the a-naphthoxazole series, a nucleus of the fl-naphthoxazole series, a nucleus of the a-naphthoselenazole series, a nucleus of the fi-naphthoselenazole series, a nucleus of the thiazoline series, a nucleus of the thiazolidine series, a nucleus of the thiazole series, a nucleus of the selenazole series, a nucleus of the oxazolidine series, a nucleus of the oxazole series, a nucleus of the tetrazole series, a nucleus of the quinoline series, a nucleus of the tetrahydropyrrole series, a nucleus of the pyridine series, a nucleus of the 2,3,3-substituted 3H-benz[g]-indole series, or a nucleus of the 3,3- dialkylindolenine series.

8. The negative silver halide photographic emulsion of claim 1, wherein said ketomethyleno heterocyclic ring 19 completed by Q is a rhodanine nuclei, a 2-thio-2,4(3,5)- oxazoledione nuclei, a 2-thioxydantoin nuclei, a 5-pyrazolone nuclei, a 4-thiazolidone nuclei, a 2-amino-4(5)- thiazole nuclei, a 2-alkylmercapto-4(S)-thiazole nuclei, or a barbituric acid nuclei.

9. The negative silver halide photographic emulsion of claim 1, wherein said heterocyclic ring completed by Z, or Z is selected from the same nuclei as is the ring completed by Z as defined in claim 7.

20 3,501,309 3/1970 Gilman et al. 96137 3,557,101 1/1971 Taber et a1 96127 3,501,305 3/1970 Illingsworth et a1. 96-107 FOREIGN PATENTS 1,027,146 4/1966 Great Britain 96-107 OTHER REFERENCES Ia: Properties of Photographic Emulsion Grains A Photographic light-Sensitive element comprising 10 in The Journal of Photographic Science, vol. 12, 1964,

a support bearing thereon a silver halide emulsion of claim 1.

References Cited UNITED STATES PATENTS 3,501,306 3/1970 Illingsworth 96-107 3,501,312 3/1970 Mee et al. 96127 3,501,310 3/1970 Illingsworth et al. 96137 J. TRAVIS BROWN, Primary Examiner W. H. LOWE, JR., Assistant Examiner 15 U.S. Cl. X.R. 

